Table Of ContentTitles in the IF A C Proceedings Series
AKASHI: Control Science and Technology for the Progress of ISERMANN: Identification and System Parameter Estimation
Society, 7 Volumes (1979)
ALONSO-CONCHEIRO: Real Time Digital Control Applications ISERMANN & KALTENECKER: Digital Computer Applications to
ATHERTON: Multivariable Technological Systems Process Control
BABARY & LE LETTY: Control of Distributed Parameter Systems JANSSEN, PAU & STRASZAK: Dynamic Modelling and Control of
(1982)
National Econornics
BANKS & PRITCHARD: Control of Distributed Parameter JOHANNSEN & RIJNSDORP: Analysis, Design, and Evaluation of
Systems
Man-Machine Systems
BEKEY & SARIDIS: Identification and System Parameter
LAUBER: Safety of Computer Control Systems
Estimation (1982)
LEININGER: Computer Aided Design of Multivariable
BINDER: Components and Instruments for Distributed Computer
Control Systems Technological Systems
CAMPBELL: Control Aspects of Prosthetics and Orthotics LEONHARD: Control in Power Electronics and Electrical Drives
Van CAUWENBERGHE: Instrumentation and Automation in the LESKIEWICZ & ZAREMBA: Pneumatic and Hydraulic
Paper, Rubber, Plastics and Polymerisation Industries Components and Instruments in Automatic Control
CICHOCKI & STRASZAK: Systems Analysis Applications to MAHALANABIS: Theory and Application of Digital Control
Complex Programs MILLER: Distributed Computer Control Systems (1981)
CRONHJORT: Real Time Programming (1978) MUNDAY: Automatic Control in Space
CUENOD: Computer Aided Design of Control Systems NAJIM & ABDEL-FATTAH: Systems Approach for Development
De GIORGO & ROVEDA: Criteria for Selecting Appropriate (1980)
Technologies under Different Cultural, Technical and Social NIEMI: A Link Between Science and Applications of Automatic
Conditions Control
DUBUISSON: Information and Systems NOVAK: Software for Computer Control
ELLIS: Control Problems and Devices in Manufacturing Technology O'SHEA & POLIS: Automation in Mining, Mineral and Metal
(1980) Processing
FERRATE & PUENTE: Software for Computer Control OSHIMA: Information Control Problems in Manufacturing
FLEISSNER: Systems Approach to Appropriate Technology Technology (1977)
Transfer
RAUCH: Control Applications of Nonlinear Programming
GELLIE & TAVAST: Distributed Computer Control Systems (1982)
REMBOLD: Information Control Problems in Manufacturing
GHONAIMY: Systems Approach for Development (1977)
Technology (1979)
HAASE: Real Time Programming (1980)
RIJNSDORP: Case Studies in Automation related to Humanization
HAIMES & KINDLER: Water and Related Land Resource Systems
of Work
HALME: Modelling and Control of Biotechnical Processes SAWARAGI & AKASHI: Environmental Systems Planning, Design
HARDT: Information Control Problems in Manufacturing and Control
Technology (1982) SINGH & TITLI: Control and Management of Integrated Industrial
HARRISON: Distributed Computer Control Systems Complexes
HASEGAWA: Real Time Programming (1981) SMEDEMA: Real Time Programming (1977)
HASEGAWA & INOUE: Urban, Regional and National Planning SUBRAMANYAM: Computer Applications in Large Scale Power
Systems
— Environmental Aspects
TITLI & SINGH: Large Scale Systems: Theory and Applications
HERBST: Automatic Control in Power Generation Distribution and
Protection Van WOERKOM: Automatic Control in Space (1982)
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IF AC Related Titles
BROADBENT & MASUBUCHI: Multilingual Glossary of Automatic Control Technology
EYKHOFF: Trends and Progress in System Identification
ISERMANN: System Identification Tutorials (Automatica Special Issue)
INFORMATION CONTROL PROBLEMS
IN
MANUFACTURING TECHNOLOGY 1982
Proceedings of the 4th IF A C/IFIP Symposium
Maryland, USA, 26-28 October 1982
Edited by
D. E. HARDT
Massachusetts Institute of Technology,
Cambridge, Massachusetts, USA
Published for the
INTERNATIONAL FEDERATION OF AUTOMATIC CONTROL
by
PERGAMON PRESS
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Copyright © 1983 IFAC
All Rights Reserved. No part of this publication may be
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First edition 1983
Library of Congress Cataloging in Publication Data
Main entry under title:
Information control problems in manufacturing technology
1982
(IFAC proceedings series)
Includes index.
1. Automation —Congresses. 2. Robots, Industrial —
Congresses. I. Hardt, D. E. (David E.) II. International
Federation of Automatic Control. III. International
Federation for Information Processing. IV. Series.
T59.5.I46 1983 629.8'3 83-11398
British Library Cataloguing in Publication Data
Information control problems in manufacturing
technology 1982.
— (IFAC proceedings series)
1. Automation — Congresses
2. Production engineering — Congresses
I. Hardt, D. E.
II. International Federation of Automatic Control
III. International Federation for Information Processing
670.427 T59.5
ISBN 0-08-029946-6
These proceedings were reproduced by means of the
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Therefore, the readers are asked to excuse any deficiencies
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Printed in Great Britain by A. Wheaton & Co. Ltd., Exeter
FOURTH IFAC/IFIP SYMPOSIUM ON INFORMATION
CONTROL PROBLEMS IN MANUFACTURING
TECHNOLOGY
Organized by
The National Bureau of Standards, U.S. Department of Commerce
Sponsored by
The International Federation of Automatic Control (IFAC) through
Technical Committee on Manufacturing Technology
Technical Committee on Theory
Co-sponsored by
The International Federation for Information Processing (IFIP) through
Technical Committee 5.3 on Discrete Manufacturing
The National Bureau of Standards, U.S. Department of Commerce
International Programme Committee National Organizing Committee
A. D'Auria, Italy J. Albus (Chairman)
A. Bensoussan, France J. L. Nevins (Vice-Chairman)
Dr. Chalupa, Czechoslovakia M. Auman (Secretary)
J. Hatvany, Hungary S. R. Torrence
M. Horväth, Hungary G. D. Pignone
W. Karner, Austria K. F. J. Heinrich
I. Kato, Japan
D. Kochan, G.D.R.
D. McPherson, U.K.
L. Nemes, Hungary
J. L. Nevins (Chairman), U.S.A.
D. E. Okhotsimsky, U.S.S.R.
Y. Oshima, Japan
T. Pfeifer, F.R.G.
U. Rembold, F.R.G.
A. Romiti, Italy
C. Rosen, U.S.A.
T. Sata, Japan
J. Scrimgeour, Canada
J. Skakala, Czechoslovakia
J. Somlo, Hungary
J. Thoma, Swizerland
D. R. Towill, U.K.
G. VanderBrug, U.S.A.
J. L. Remmerswaal, Netherlands
H. J. Warnecke, F.R.G.
PREFACE
The field of manufacturing has recently seen an explosion of activity, spurred on by
the influence of inexpensive computing devices and the hope that through application
of modern engineering science the operation of our factories can become more efficient
in labor, material and energy use, while at the same time being responsive to the
needs of the product consumers. The topics in this year's symposium are particularly
appropriate to this theme.
Any significant advance in technology is founded upon adequate support of basic
research. In Section 1 the various US government programs now sponsoring manufacturing
related research are covered. This support covers the range from basic process physics
research to general questions of artificial intelligence in the manufacturing
environment.
At the heart of any manufacturing operation are the unit processes. Proper control
of these processes is vital to achieving the autonomy that will eventually lead to
automated manufacturing systems. In Section 2 these issues are addressed in terms
of the general control problem involved and in the solution of specific processing
problems. The cornerstone of process improvement is improved measurement and
inspection methods. Section 3 presents examples of both on and off-line techniques
that use novel methods of data acquisition and signal processing.
The growing role of industrial robots in advanced manufacturing systems is pointing
up many problem areas in need of research. In Section 4 several of these areas are
covered, including fundamental questions of manipulator design and control, and
modelling of robot work environment. This reflects a realization that a major
obstacle in the way of widespread use of robots is inadequate understanding of the
mechanics of the task environment as well as the device itself.
The ability to integrate processes and robots into an efficient manufacturing system
is truly the challenge of the future. In Section 5 a wide range of such problems
are addressed including planning, scheduling, inventory, and decision systems. In
Section 6 specific examples of fully automated manufacturing and assembly systems
are presented, providing a measure of our current state of the art, and a window on
the near future.
D.E. Hardt
Cambridge, Massachusetts
Copyright © IFAC Information Control Problems in SESSION 1 - GOVERNMENT ACTIVITIES
Manufacturing Technology, Maryland, USA 1982
DEFENSE ADVANCED RESEARCH PROJECTS
AGENCY PROGRAM - INTELLIGENT
TASK AUTOMATION*
E. C. Levinthal and E. C. van Reuth
Defense Sciences Office, Defense Advanced Research Projects Agency,
1400 Wilson Boulevard, Arlington, Virginia 22209, USA
Abstract. The establishment of a science and technology base for many aspects of
defense manufacturing and for adapting intelligent systems for complex military
operational tasks is a cornerstone effort of advanced research with great national
significance. This presentation provides an overview of the efforts of the Defense
Advanced Research Projects Agency (DARPA) and the Air Force Wright Aeronautical
Laboratories (AFWAL) to plan and fund technology development for a substantial leap
in Intelligent Task Automation (ITA). In addressing the needs for high productivity
in manufacturing and robust applications to complex military tasks, the ITA program
develops and integrates the generic technologies impacting, gripping, sensing,
viewing, recognizing and understanding the environment, controlling manipulation,
and intelligently providing command of the task.
Keywords. Artificial intelligence; assembling; cybernetics; manufacturing processes;
process control; robots; sensors; system analysis; vision.
INTRODUCTION in a recent "Overview" of robotics prepared
by the National Bureau of Standards in
Automation and automatic control of industri conjunction with the National Aeronautics
al processes has been permeated by robotic and Space Administration (Gevarter, 1982).
concepts, with the intent of providing In this report, the industrial needs and
greater industrial productivity for a expectations are compared with directions
"^industrialization in America." Flamboyant being taken in research and development.
feature articles in the popular press and Emerging in the foreseen evolution are
some technical literature raise the expec hands with improved dexterity, the advanced
tation that future robots will be sophisti control systems to support them, the vision
cated, dexterous, adaptable and intelligence and touch sensors to support the programmed
for a wide gamut of industrial, military control, and (later) a self-planning for
and community operations -- on Earth and in intelligently supporting more general
space. Some caution is needed in estimating commands.
the time scale for those events. It is nec
essary to take into account the inertial There are various tasks being considered
forces that resist change in production for application of the expected intelligent
methods, military operations and social capabilities in automation. In manufacturing
behavior. These conservative forces limit they range from providing speed and economy
the considerable support that is necessary in mass production assembly tasks to
to transfer what is possible in the labora totally automating inventory and tool
tory into actual practice. DARPA1s role is management in manufacturing. In military
to remove some of the constraints so that operations they include handling such
these promises of the future are realized complex tasks as reconnaissance and sweeping
sooner and more fully. mine fields.
Forecasts of unfolding robot technology Getting the technology trends to provide
were brought under rational considerations the anticipated payoffs in automation of
intelligent tasks is not straightforward.
In terms of R&D economics, there are strenuous
*This paper is also presented at the Fourth issues as to whether the advanced concepts
Meeting of the Coordinating Group on Modern and developments providing economical
Control Theory held at Oakland University, soundness of approach for manufacturing
Rochester, Michigan, Oct 26-28, 1982, by industries will sufficiently support a
Dr. E. C. van Reuth. robust realization of the possibilities.
ICPMT-A*
1
2 E.C. Levinthal and E.C. van Reuth
For instance, re-engineering the production and tools to include the Army's thinking
methods within existing plants presents con about automating the "land rover." Where
siderable economic competition for the initially, remotely controlled mine clearing
robotic alternatives of installing flexible may be obtained by outfitting armored
automation that copes with the unstructured vehicles with a roller or mine plow and
environment. Manufacturing, for some time dispensing mine-clearing line charges, the
to come, may in the large remain permissive eventual concepts will be intelligent about
enough to support vision with structured the overall countermine objective of estab
light or to take advantage of 2-D images at lishing passage through a mined area.
fixed range -- in spite of the significant Instead of blindly clearing an intended
efforts in laboratories to secure the area, many mines could be located by de
necessary technologies for understanding tecting the mine "footprint" with appropriate
3-D images with grey scale. sensors and then marking the mine for
avoidance. This intelligent approach would
DARPA'S ROLE be based on an integrated automation of the
roving vehicle, information handling, and
As the central research organization for physical handling of markers and cover
the Department of Defense, DARPA has a material at a mine location.
primary responsibility to support advanced
research bearing on manufacturing because In pointing out the enormous possible
of the significant military value of the breadth of applications, it is intended not
industrial base to military force structure. to thoroughly define the scope for using
The present joint project linking DARPA DARPA's resources, but rather to provide
with the Air Force Wright Aeronautical some insight to the range of choice being
Laboratories (AFWAL) at Wright Patterson addressed. The Defense Sciences Office
Air Force Base is in large part due to the (DSO) has arrived at a focus in terms of
challenge of meeting our nation's defense the following concept for Intelligent Task
readiness goals through integrated computer- Automation (ITA). While not excluding
aided manufacturing (ICAM). Solving problems other interests, this focus is usefully
in the production base and developing providing a point of departure for prior
tomorrow's new, more efficient manufacturing itizing technological opportunities. The
processes for the military hardware that DSO program is coordinated with the efforts
will be required at the turn of the century of the Information Processing Techniques
is a vital support activity for DARPA. Office (IPTO) of DARPA. IPTO's programs in
artificial intelligence, information pro
cessing and computer technologies have an
In addition, the military services look to
important impact on the ITA goals. The
DARPA for the kind of technological advances
emphasis of DSO is presently on device sub
that will extend and enhance operational
systems with ITA capabilities and, in the
capabilities in the combat environment.
future, on complete systems.
Presently, the military is looking into the
implications of robotic technology and
recognizes that today's technology, except THE ITA CONCEPT
for a few innovations in space, is dedicated
to the assembly line and will remain there Among the technological advances in
unless military needs are defined and automation promising operational payoffs
developments funded. in either defense manufacturing or military
operations are some potential advances
For the near term, the military is expected that may not get bridged "naturally" by
to adopt the industrial robotic technologies industrial support and incentives. As
for the same advantages found in manufactur pointed out above, such tradeoffs in the
ing -- relieving personnel from hazardous industrial environment as using advanced
tasks that demand time-critical effort. robotic sensing versus engineering the
Handling ammunition resupply for self- robot's environment are not likely to
propelled artillery or tanks has been arrive at the same critical demand that
the military has for sensor driven control.
considered as a direct application of the
Without the means to structure its environment,
industrial robots. The continuous-path
the military robot is confronted with
capabilities currently available appear
obstacles, clutter, or unknown conditions;
suited to transferring ammunition from
and its target will have highly variable
armored resupply vehicles to armored combat
character. Exploitation of the kinds of
vehicles in the battlefield environment
sensory controls outlined by D. Nitzan
under possible threat of nuclear, biological,
(1981) will be a military necessity; and
or chemical (NBC) actions. Essentially,
it can be anticipated that the economic
these tasks call for the mobile mounting of
tradeoffs for industry will also eventually
an industrial robot for forward operations
prove out the advantages of gaining flexibil
with the combat support forces.
ity with extensive sensing.
But the military is especially interested
in such broader applications of automation Simply, DARPA is recognizing that some
technologies as providing intelligent technological opportunities are apparently
solutions to the Army's countermine problem. missing investments because of the compe
Concepts for solving this problem will go tition of attention to near-term engineering
beyond the physical handling of material "problems." Technologies suitable for
Defense Advanced Research Projects Agency Program 3
military operations and the longer term intended task is specifically sought;
goals for flexible manufacturing should and, the technological opportunities are
not take advantage of structures for the expected in linking computation to mechanical
environment. For example, the "bowl" function. The choice of scope in carrying
feeder used in part-sorting in industrial out this objective is depicted in Figure 1
assembly is unlikely to work out for an and described in the following sections of
ammunition handler in the combat arena. this paper.
To obviate structured solutions, the
research program places an emphasis on END MANIPULATOR CONTROL
integrating vision, touch, and proximity
sensing in process control. Sensor inte Available technologies present a broad
gration is apparently a prime target in gamut of limitations to achieving the
the generally held consensus about gaining "smart hands" called for in intelligent
flexibility. For instance the NBS/NASA task automation. The needed dexterity
report (Gevarter 1982) notes such aims in entails rapid movement within the context
its synthesis of needed research that drew of the work space, sensitive force control
on surveys and recommendations of conferences and fine movement enabling the "give"
and workshops during the previous three needed for inserting or mating parts, and
years. The implied emphasis is on the a secure grasp that accomodates irregular
integration as well as the generation of objects. In contract to these needs,
manipulators now primarily respond to
sensory data -- that is, on linking the
position control , requiring that the
computation of an understanding of the
robot's environment be engineered to the
environment to the mechanical function.
same high accuracy as the robot. Large
and heavy structures are used to provide
In summary, the DARPA program in intelligent
stiffness so that end point locations can
task automation seeks technology development
be accurately inferred from joint angles.
representing a substantial leap forward
Thus, movements are slow and clumsy; and
from current capabilities with a focus on
position accuracy is only as good as the
realizing automation in unstructured
accumulation of errors and the stiffness
environment. The necessary intelligence
of the members. Designs for multifinger
to deal with both uncertainty of the
hands, suitable for grasping, have only
environment and sophistication of the
INTELLIGENT TASK AUTOMATION
SENSORY CONTROLLED
§ · t
MANIPULATION
COMMAND
INTELLIGENCE
INTERPRE SENSORS STABILITY END POINT FUNCTIONAL MOTORS
TATION FOR CONTROL OF CONFIGURA
FLEXIBLE MULTIPLE TIONS
STRUCTURES LINKS
VISION TOUCH PROXIMITY
Figure 1. Couplings in DARPA Program
4 E.C. Levinthai and E.C. van Reuth
progressed to the ability to impart some necessitate sensing force and contact for
limited motion by a heuristic combination feedback. Several architectures for
of position and force-controlled fingers. position and force control of the multiloop
mechanisms are being investigated. Pre
End point control of the manipulator and liminary results are appearing for the
the individual fingers is the key to quick joint's torque subsystem. The physical
and precise actuation with lightweight dimensions of multi-fingered hands can be
structures. It is not yet available optimized on the basis of kinematic per
because robust (stable) control of the formance and the volume of grasp.
flexible structures has not been possible.
When torque at one end of a series of
links is based on feedback at the other END SENSING
end, any flexibility in the series makes
the system inherently unstable. The Force and contact sensing are also being
techniques for stable control using end- explored for perceptual information.
point sensing are difficult to perfect. Components for force sensing are now being
DARPA is now sponsoring research to directly perfected that provide force measurements
address the integration of end point without friction and with little mass
sensing with efficient stable control. between sensor and load. At the command
or strategy level in automation for a
Specific attention is being turned to task, contact sensing provides the infor
developing minimum time algorithms for mation for inference and estimation of
slewing a flexible robotic arm through a geometric and dynamic properties of loads
large angle and then touching an object and the environment. Contact of individual
softly. That is, large impulsive "crashes" fingers provides an estimate of local
are to be avoided at the contact. To surface curvature and orientation, while
handle uncertainty in the target object's several point contacts on several fingers
location, the research will incorporate provide gross orientation and curvature,
end-point sensors such as optics, simple e.g. fingers wrapped around a cylinder.
range finders, strain-gauge-equipped Integrated data from fingers moving over a
fingers and proximity sensors. New surface should reveal surface shape and
design concepts for arms are expected dynamic properties of objects. As this
that will enable controlling higher terminal research progresses, it is expected that
speeds without large impact forces even strategies in hand control will evolve
when there is uncertainty in the target's from experiements. Manipulation rules for
location. For example, mass distributions re-orientation of grasped objects within
and flexibility will be varied in design the hand is one of the goals.
trade-off studies.
Integrating vision, range sensing and
Since a number of control modes must be proximity sensing with the force and
involved, beginning with a large positional contact sensing is also being addressed.
slew and ending with force control, methods There are two levels of intended integration
are under investigation for smooth switching in the hierarchy of command and control --
between control regimes while the mechanism at the command level for intelligent
is in motion. Initial objectives are to planning of the task actions, and at the
obtain the minimum-time algorithm for the control level for tracking.
"slew and touch" task. Further investigation
of new arm designs will then take advantage Vision and image analysis are major research
of flexibility and distribution of arm areas of the same magnitude as the intended
control to best accomplish specific tasks. focus on ITA (see, for instance, the
survey by T. Binford, 1982). Results from
As control techniques are developed that vision research at leading institutions
are tolerant of flexibility in a manipula will be extensively drawn into the investi
tor's mechanical structure, manipulators gations of the command and control processes
can be lightened and made faster. They for ITA. Understanding how vision integrates
will be safer to use, less prone to damage with other sensors is the major objective,
from collisions, require less power to rather than the vision science per se. In
run, and cost less to fabricate. particular, the research foundations for
the use of models in sensory processing
Control of force sensing fingers is also and interpretation are being explored in
being explored under the current DARPA relation to representations of sensor
sponsorship. The control theory for estimates as geometric constraints.
coordinated motion of complex hands developed
by Salisbury and Craig (1982) at Stanford
University is being pursued. The theory RANGING AND 3-D SENSING
specifies position and force control for
the coordinated motions desired in such The practical benefits of ranging systems
tasks as insertion where the goal is to are beginning to be recognized. The data
minimize transverse forces while exerting so gathered may be organized in depth
a force in the intended direction of the maps, range images or like forms of 3-D
insertion. Such tasks require force "vision." Three-dimensional sensing has
control throughout the relative motion and the same aim as other forms of computer
Defense Advanced Research Projects Agency Program 5
vision -- the higher level representation (1978) and S. Buckley at MIT. A manipulator
of the scene for purposes of comparison or was positioned by phase measurements from
recognition. the acoustic sensor array, locking onto
an objects position. All the necessary
When a manipulator is on the move in elements of a robot for assembly were
dealing with a dynamic situation, it is demonstrated and later work at MIT showed
necessary that it work with shape in its that the sensor system could provide
three dimensional space. The system sufficient accuracy for commercial robots.
should be capable of dealing with information
acquired piecemeal from different vantage Now software is under development for
points. In fact, arrangements as have detailed processing of the sensor data and
been tried by G. Agin (1979), among others, for integrated control of a commercial
have shown the advantages of moving the robot. The software development is including
sensors for the express purpose of obtaining the development of various algorithms to
more detailed information about the environ interpret phase information and couple
ment, such as seeing around occluding control to the robot. The investigations
objects. are addressing "matrix" algorithms for
interpreting phase information, and "proximity"
In research receiving support by DSO and algorithms to detect range and direction
IPTO jointly, a goal is set on classifying data in less structured environments. The
objects and determining their position and goal of the proposed work is to demonstrate
orientation with a ranging system. The assembly of mating parts with response
activity is constructing a sensing system sufficiently rapid for industrial application
for generating light-stripe range data (typically one second for shaft or bearing
from multiple points of view and exploring assembly).
concepts for gaining speed and accuracy in
its operation. The data analysis develop
ments are devising advantageous data MICRO-MINIATURE MOTORS
structures for indexing the data and
controlling image scanning. Generalized Mechanical concepts for the dexterous hand
cylinders make up the low-level primitives have made extensive progress. The jointly
in range data. conceived "Stanford-JPL hand" has appeared
prominently in the popular press, presumably
Identification of objects is sought on by virtue of appearing to borrow heavily
the basis of a preponderance of evidence from nature by using tendon-like cables to
from a matching process. actuate its fingers. Motors are mounted
on the forearm to avoid encumbering the
fingers. The tendon-like design allows
three joints, on each of three fingers,
with an overall geometry similar to that
PROXIMITY SENSING IN of a human hand. The nine degrees of
ASSEMBLY freedom provide a firm basis for dexterity.
Of special interest is the role of proximity The "tendons" are cables and the electro
sensing in relation to the vision perspective mechanical devices are conventional motors,
at relatively long ranges and the perspective nonetheless. Electric motors have a
of touch sensors at contact. Short-range number of inherent problems which limit
proximity and part-presence sensors can their effectiveness in application to
possibly overcome finger shadowing of a fine-motion manipulators. Such limitations
vision sensor and may enhance the ability are addressed by another research effort
to cope with unstructured or cluttered currently supported by DARPA aimed at
fields of view as occur with some assembly capitalizing on the lessons from biology
tasks. Operations involving the important about the structure and scale of natural
assembly tasks of mating shafts into holes muscle.
and bearings onto shafts without jamming
can benefit from improvements in accuracy While electric motors are well suited for
and speed. Current capabilities for such applications such as fans, disc drives,
automation of assembly particularly lack pumps, etc., their relatively low output
ability to detect whether the assembly has torques require use of transmission systems
proceeded properly. for the high-torque and low-speed operation
in a servosystem or robotic application.
A current objective of DARPA supported Transmission systems introduce a number of
research is to demonstrate the capabilities serious limitations on electric motors by
of an acoustic sensing method based on compromizing the dynamic performance.
phase monitoring as a means of detecting Dynamic characteristics of the motor such
and controlling the performance of robotic as armature inertia and damping are affected
assembly. Demonstration of shaft and by the square of the transmission ratio.
bearing mating is intended. The research Transmissions also impact efficiency. For
extends the technology of an automated example, high performance planetary trans
positioning system based on phase monitoring mission, utilized extensively in today's
of an array of acoustic sensors (microphones) aircraft industry, drop efficiencies into
as developed earlier by J. Tavormina the range of only 50%.
